Where is the memory located?

Hello everyone. I have been having a great time figuring out my 16GB THRiVE that I purchased on Sunday. One thing that has me puzzled is where you can locate the memory fo the device. When I have my tablet attached to my Windows PC via the Mini USB port it allows access to "AT100" then the drive "Device Storage". The item "Device Storage" only reads available total space capacity of 9.98GB.

I have noticed if you explore "Device Storage" and you have a SDCARD inputed you will have a directory called "sdcard-disk0﻿". This directory does allow the writing to the SDCARD slot without taking up internal memory.

What I am really wanting to know is if the device is reading 10GB free space, where is the other 6GB? Can we write to this space?

I have been using the Android OS for 3 years starting with the G1 and recently the Nexus S. With these devices there was a bit of internal memory allocated that the user could not access or modify, does the THRiVE tablet also have this in effect?